As a machining tool with such a replaceable machining head mounted on the tool body, for example, Patent Document 1 discloses a machining head replaceable rotating tool. In this tool, a male screw for fastening and a female screw for fastening are provided coaxially on one and the other of a machining head (replaceable machining head) and a holder (tool body) to screw them together; and then the machining head is attachably and detachably mounted coaxially on the front end of the holder.
Here, in the machining head replaceable rotating tool described in Patent Document 1, the machining head and the holder each have an abutting face where they abut each other in a fastened state so that the male screw for fastening and the female screw for fastening are screwed together. The machining head performs predetermined machining by rotating the machining head mounted on the holder as one unit in a rotational direction in which the male screw for fastening and the female screw for fastening are screwed into each other by a rotational machining load. Further, both abutting surfaces on which they abut prevent the male screw for fastening and the female screw for fastening from being screwed too tightly by the rotational machining load.
Patent Document 1 also describes that the body of the replaceable machining head has a tool locking portion (attaching portion) in which a working tool such as a wrench is to be locked, for screwing the male screw for fastening and the female screw for fastening together. The tool locking portion has a pair of parallel flat tool locking faces (attaching faces) shaped as two chamfer parts, which are symmetrical with respect to the axis. Further, Patent Document 1 describes that, according to the kind of tool used, the head body includes such components as cutting edges, and is made of a designated tool material, for example, cemented carbide or high-speed steel. Also, as the need arises, the head body can be coated with a coating film such as a compound film coating, for example TiN, TiCN, TiAlN, CrN, etc., or a hard film coating, for example DLC film, diamond coating, etc.